Image by Getty / InfoWars / FuturismGeneticsA mouse with two dads or a bi-paternal mouse,in the scientific parlance has made it to adulthood. Several mice, in fact.As detailed in a study , scientists achieved this feat of same-sex murine parentage by using CRISPR techniques to rein in rogue genes that undergo a troublesome process known as imprinting.We're still far from replicating this feat in humans, but it marks a milestone in same-sex reproduction in mammals. Until now, many similar attempts have resulted in unhealthy offspring."The unique characteristics of imprinting genes have led scientists to believe that they are a fundamental barrier to unisexual reproduction in mammals," said study coauthor Qi Zhou of the Chinese Academy of Sciences in a statement about the work. "Even when constructing bi-maternal or bi-paternal embryos artificially, they fail to develop properly, and they stall at some point during development due to these genes."The Chinese scientists aren't the first to bring up bi-paternal mice that lived to adulthood; a team from Japan made that breakthrough in 2023. But the latest approach is novel, and could provide insights into preventing developmental diseases in humans. It's not a direct road to helping human same-sex parents conceive children, but the authors believe it will carry over to monkeys, which they hope to experiment on next.The scientist's unique approach involved genes that undergo imprinting. For context, we normally inherit a copy of a gene from each parent. But sometimes, when only one of the pair is expressed while the other is silenced, you have imprinting. The resulting imbalance can often cause developmental defects, which plagued previous attempts at creating a bi-paternal mouse. Simply put, it causes too many genes to go haywire.To address this, the researchers first grew stem cells from sperm DNA. They then edited the stem cells to prevent twenty mice genes known to be heavily involved in their developmental stage from being imprinted.While it's just a portion of the total number that undergo this process in mice, according to MIT Technology Review, it made an impact. The stem cells successfully created embryos after being injected into lab grown egg cells which were then fertilized with another male's sperm.This technique is far from perfect, though. Only around 12 percent of the embryos were able to make it to birth, and some of those that did still exhibited developmental defects. Most of the adults had a short lifespan, and all the adult mice ended up sterile. (Unlike in the 2023 study, in which the adults were able to produce offspring.)So it's not quite one big happy family. But this is just a start in what could be a game-changer in not just refining unisexual reproduction, but understanding imprinting's role in many human diseases."These findings provide strong evidence that imprinting abnormalities are the main barrier to mammalian unisexual reproduction," said coauthor Guan-Zheng Luo of Sun Yat-sen University in Guangzhou in the statement. "This approach can significantly improve the developmental outcomes of embryonic stem cells and cloned animals, paving a promising path for the advancement of regenerative medicine."More on genetics: Designer Babies Running Into Trouble Now That They're TeenagersShare This Article